1. Field of the Invention
The present invention generally relates to a display device, and more particularly, to a plasma display panel.
2. Description of the Background Art
Generally, the plasma display panel is a display device which includes an upper substrate, a lower substrate, and a barrier rib that is produced between the upper substrate and the lower substrate. Each cell is mainly filled with discharge gas such as Ne, He, or Ne+He and also contains inert gas, such as small amount of xenon. Upon being discharged by applying high frequency voltage, the inert gas generates ultraviolet rays (preferably vacuum ultraviolet rays), thereby to emit light by fluorescent substance on the lower substrate and/or the barrier ribs to realize an image. Such plasma display panels are relatively thin and lightweight and are preferable as next generation display device compared to CRT or LCD.
FIG. 1 is a structural diagram that shows the electrode arrangement of a plasma display panel. As shown, the electrode arrangement of plasma display panel includes a plurality of scan electrodes Y1 to Yn and a plurality of sustain electrodes Z1 to Zn, which are respectively paired. The scan electrodes and the sustain electrodes are originated from the scan electrode pad 21 and sustain electrode pad 22 and on the upper substrate 20. The distance between the plurality of scan electrodes is uniformly maintained within error range through the upper substrate 20, and the distance between the plurality of sustain electrodes is uniformly maintained within the error range through the upper substrate 20. Further, the distance between the scan electrodes and the sustain electrodes maintain uniformly.
In a plasma display panel with such electrode structure, the electrode structure within discharge cell is shown in FIG. 2. The electrode structure within discharge cell of the plasma display panel include a bus electrode b of the scan electrode 101 and the sustain electrode 102 formed on both side of the discharge cell, respectively on an upper substrate, and a transparent electrode a of the scan electrode 101 and the sustain electrode 102 formed respectively on both side which each bus electrode b are formed so that they are opposite each other while leaving center of a discharge cell between them.
Corresponding address electrode on a lower substrate crosses with the bus electrode b and the transparent electrode a within each discharge cell. Although not shown, the cell has fluorescent materials within the discharge cell for emitting R, G, and B rays upon cell discharge.
In the plasma display panel with such electrode structure within discharge cell, if corresponding voltages are provided to corresponding transparent electrode a of the scan electrode 101 and the sustain electrode 102 and the corresponding address electrode within a cell, a discharge occurs in the cell and the fluorescent materials emit light, thereby to display image.
The luminance property in each section of the plasma display panel is shown in FIG. 3. If the corresponding signals, i.e. signals of 180V, 1.14 A, are applied to each of the scan electrodes and the sustain electrodes, sections A1 to A5 exhibits an average luminance of 159.2, sections A6 to A10 exhibits an average luminance of 156.2, sections A11 to A15 exhibits an average luminance of 153, sections A16 to A20 exhibits an average luminance of 157.4, and sections A21 to A25 exhibits an average luminance of 160.8. In other words, if the same signals are applied to the scan electrodes and the sustain electrodes formed in the plasma display panel, each section in the upper substrate 100 of the plasma display panel exhibits different luminance.
Such luminance irregularity to be exhibited in all sections of the upper substrate corresponding to a display plane of the plasma display panel causes deterioration of image quality, and decreased reliance of the plasma display panel.